James & Holmstrom Transposing Upright
||James & Holmstrom
By rotating the wheel located on the underside of the keybed, the keys can be moved left or right to change the pitch of the piano keys.
In the normal position there is a small pointer aimed at A. The keys can be moved to cause the pointer to aim as low as F# or as high as B.
When the wheel is rotated, a rack and pinion located under the keys accomplish the motion of the key frame.